[feature] Add an initialPacket option (#471)

README.md

@@ -227,6 +227,7 @@ to a single process.
         Set false to not save io cookie on all requests. (`/`)
       - `cookieHttpOnly` (`Boolean`): If `true` HttpOnly io cookie cannot be accessed by client-side APIs, such as JavaScript. (`true`) _This option has no effect if `cookie` or `cookiePath` is set to `false`._
       - `wsEngine` (`String`): what WebSocket server implementation to use. Specified module must conform to the `ws` interface (see [ws module api docs](https://github.com/websockets/ws/blob/master/doc/ws.md)). Default value is `ws`. An alternative c++ addon is also available by installing `uws` module.
+      - `initialPacket` (`Object`): an optional packet which will be concatenated to the handshake packet emitted by Engine.IO.
 - `close`
     - Closes all clients
     - **Returns** `Server` for chaining

lib/server.js

@@ -49,6 +49,7 @@ function Server (opts) {
   this.cookieHttpOnly = false !== opts.cookieHttpOnly;
   this.perMessageDeflate = false !== opts.perMessageDeflate ? (opts.perMessageDeflate || true) : false;
   this.httpCompression = false !== opts.httpCompression ? (opts.httpCompression || {}) : false;
+  this.initialPacket = opts.initialPacket;
 
   var self = this;
 

lib/socket.js

@@ -65,6 +65,10 @@ Socket.prototype.onOpen = function () {
     pingTimeout: this.server.pingTimeout
   }));
 
+  if (this.server.initialPacket) {
+    this.sendPacket('message', this.server.initialPacket);
+  }
+
   this.emit('open');
   this.setPingTimeout();
 };

test/server.js

@@ -397,6 +397,18 @@ describe('server', function () {
           });
       });
     });
+
+    it('should send a packet along with the handshake', function (done) {
+      listen({ initialPacket: 'faster!' }, function (port) {
+        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+        socket.on('open', function () {
+          socket.on('message', function (msg) {
+            expect(msg).to.be('faster!');
+            done();
+          });
+        });
+      });
+    });
   });
 
   describe('close', function () {
@@ -485,7 +497,7 @@ describe('server', function () {
     });
 
     it('should trigger on both ends upon ping timeout', function (done) {
-      var opts = { allowUpgrades: false, pingTimeout: 500, pingInterval: 10 };
+      var opts = { allowUpgrades: false, pingTimeout: 50, pingInterval: 50 };
       var engine = listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         var total = 2;